Friction shock-absorbing mechanism



' Fem 15, 1927, .1,617,541

.4. F. @CONNOR FnIcTIoN sHocK ABsoRBING MECHANISM Filed Marcnzo, 1925Patented Feb. 15, 1927.

JOHN F. OCONNOR, OF CHICAGO, ILLINOIS, ASSIGNOR TO W. I-I. MINER, INC.,0 CHICAGO, ILLINOIS, A COR'PORATION OF DELAWARE.

FRICTION SHOCK-ABSORBING MECHANISIVI.

Application led. March 20, 1925. Serial No. 16,880.

This invention relates to improvements in friction shock absorbingmechanisms.

One object of the invention is to provide a friction shock absorbingmechanism of high capacity, particularly adapted for railway draftriggings, having relatively light initial or preliminary resistance,followed by heavier frictional resistance during the remainder of thecompression stroke.

Another object of the invention is to provide a mechanism of thecharacter indicated, wherein a light preliminary action and a finalheavier resistance arefhad during the compression stroke, thepreliminary action being eHected by friction elements resisted by arelatively light spring and the heavier final action being eected bycertain of said friction elements, cooperating with an additionalfriction member, having their move-V ment resisted by a heavier springelement.

' Afurther and more specific object of the invention is to provide afriction shock absorbing mechanism, including a friction shell having aplurality of friction shoes cooperating therewith, wherein certain ofsaid shoes have limited movement relative to the remaining shoes toprovide for preliminary light action and wherein all of the shoes areadapted to move in unison relatively to the shell during the remainderof the stroke to provide heavier final action, the successive inwardmovement of the shoes being effected by a wedge pressure transmittingmember having two setsV of wedge faces cooperating with the shoes.

Other objects and advantages of the invention will more clearly andfully appear from the description and claims hereinafter following. n

In the drawings, forming a part ofthis specification, Figure 1 is alongitudinal, horizontal, sectional view of a railway draft y rigging,showing my improvements in connection therewith. Figure 2 is a frontend, elevational view of the shock absorbing mechanism proper. AndFigure 3 is a transverse, vertical, sectional view, correspondingsubstantially to the line 3-3 of VFigure 1.

In said drawings, 10-10 denote channelshaped center or draft sillshaving front stop lugs 11-11 and rear stop lugs 12-12 secured to theinnerl face thereof. A portion of the drawbar is rindicated at 13, towhich is operatively secured a hooded yoke 14 of well-known form. Theshock absorbing mechanism proper, hereinafter more fully described, andfront and rear followers 15, are disposed within the yoke, the yoke andthe parts therewithin being operatively supported by a detachablevsaddle plate 16, fixed to the draft sills. As illustrated, the shockabsorbing mechanism'isof that type employing a substantially cylin.`

.drical shell and springcage casting, y and yi in order to hold thelatter in central position,v suitable guide plates 17-17 are secured tothe inner faces ofthe respective` draft sills. Y

The improved shock absorbing mechanismV proper, comprises broadly, acombined fric# tion shell and spring cage casting A; an outer series offriction shoes B-B; an inner series of friction shoes C--Cg a main wedgeD; a pressure transmitting spring follower E; a main spring resistanceF; an auxiliary spring resistance G; and a retainer bolt H. i

- oFFicE.

The combined friction Vshell and springv i cage isfin the form of acasting A having the friction shell proper 18, whichis of substantiallycylindrical form, formedfat the forward end, and the spring cage proper19, which is of substantially rectangular vboxlike form, formed at therear end. rlhe cast-i4 ing has a transverse, vertical end wall 20adapted to bear on the rear follower 15. The interior of the frictionshell 19 is provided with three independent, cylindrical frictionsurfaces 21-21, converging in-V wardly of the shell and so disposed thatthe rear ends ofthe surfaces will form acomplete, true circle.

The three friction shoes B-B are oflike construction, each shoe beingprovided with an outer, true, cylindrical friction surface 121 adaptedto cooperate with the Vcolrre-Y sponding shell friction surface21. Onthe inner side, each shoe is provided with another true, cylindricalfriction surface 22 adapted to cooperate with the corresponding shoe Cof the inner set. At theforward end, each shoe B has a curved face 23 ontheinner side thereof, the facer23 being a section of a true cylindricalsurface, and the faces 23 of the respective shoes converging inwardly ofthe mechanism ata relatively no Y Y friction; surface '.122 adaptedgtocooperate with the inner friction surface Y22l of the corresponding shoeB. Each shoe C also has a wedgefacell on the innerv side thereof, theface 24. of eachv shoev being disposed i, at a relatively bluntreleasing angle with Y reference to the longitudinal axis of the imechanism. l The main wedge D is preferablyL in the y V wedge faces1245, the wedge block is formed l three true cylindrical surfaces123`-123 mechanism,

converging inwardly' of the ada ted Yto cooperate with the cylindricalfaces 23 of the respective shoes BL As clean ly shown in Figure 1, theparts of theinechanism are'normallyisorrdisposed that the faces l2,3 and1723 are) spaced apart to permit of a limited relative movement betweenthe friction shoes@` and B1 during the initial coin- .pression of themechanism. The shoes B and istsbetween the shoesB and the frictionshellV are preferably all'. made of cast steel and the shell' made 'offcast iron. By. thisl arrangement a greater amount of' frictioneX- thanbetwe-enthe shoes B and' C, thus assury VingA relative movement of theshoes prior to any movement of the shoes Bwit-hv reference to; the shellduring release of tlieinechanism. Y However,iiiorder to assure theproper relaftive positioning of lthe friction shoes B and Viso Y ,s C',whenthe mechanism is in full release,

each of the shoes is preferably provided with a lug 26 at the` innerend' thereof adapted' to. cooperate with an annular, vtransverseShoulder 126 f'orined at the inner end of the l,friction surfacesof theshell 18;

The spring follower E is inthe form of a relatively'heavy cap having theiiange portion 27 thereof 'engaging the inner endsY oftl'ielfrictionshoes B1. The flange portion 27 isA also provided with an vannular rib281011 the VYouter sidethereof adapted to Vcooperate with ran annularshoulder 29 on. the inside ofthe spring cage, thereby limitinglthe'out-v ward movement of the spring follower. The

Y main spring resistance F",which preferably consists-of a light innercoil and a relatively heavy outer coil is interposed between the innerend' ofthe spring follower cap. E and the transverse end wallj"20of thespring cage. The auxiliary spring resistance G, which also preferablycomprises a light innerl coil and a relativelyv heavierfouter coil, hasits apposite endsbearing vrespectivelyV on the in'- ner ends of thefriction shoes G and the end wall'of the spring follower cap E, thejrearfend" ofthe spring element Gbeing accommodated within'the annularVflange 27 Vof th-e spring cap. y

In assembling the parts of the mechanism, thek mainspring resistance F'and the pressure transmitting spring follower E are inserted through anopening` in the top wall of the spring cage A', the opening being indikcated in dotted lines in Figure. It will be i evident that the frictionshoes B may be asV` seinbled with the friction shell Veither beforel orafter the spring follower `and main spring are inserted within thespring cage. After they parts have been thus assembled, thea-uioV iliaryspring resistance G, friction shoes C and vwedge D are placed vinposition, the parts being. then secured by the retainer bolt I-I. Y

The' mechanism is held under initial compression and of uniform overallYlengthby the'retainer bol-t l-l which' has its opposite `ends anchored-to the spring cage and main wedge respectively. The head of'thebolt isseated in a thimbleSO having an annular flange 31 at the rear l,endthereof, bearing on an annular'shoulder 32 surrounding an openof thespringcage. The nut at the opposite end of the bolt is accommodatedwithin the hollow portion of the wedge member D, the shankl of the boltextending through alined openings in the wedge D, spring follower E andthiinble 30.

Assuming a compression stroke of the mechanism,`the operation is asfollows: As

the followers 15 are moved relatively toward eachother, the wedge D willbe forcedlv in- B, compressing the auxiliary springv resist!V anceVagainst the spring follower E. During this time, there willbesubstantially no com;

pression of the main spring resistance Rias the same is placed under asufficient amount of initial compression whenl 'the parts are assembled'to prevent, inward: movement of the follower E at this time. rllheinward movement of the friction shoes C on the shoes B will continue,untillr the faces 128 of the wedge D. come into abutment with the faces23 of the shoes B, wheieupon the latter will be carried4 tion shell yinunison withthe friction shoes C, the frictional` resistance being thustra-ns ferredtothe shoes B and the friction shell'. As the frictionshoes are moved: inwardly of the shell, the pressure transmi ting springfollower- E which engages the inner ends o f the shoes will be carried'rearwardly thereiin 90 ing formed inthe transverse end wall 2O with,compressing the main spring F. Due to the'taper of the shell, the shoesBand C will be forced laterally inward. toward theY axis of themechanism, slipping on the Wedge faces of the wedge D, thereby causingthe .shoes to move rearwardly morel rapidly than the wedge and effectingan additional compr-ession of the spring F. The described action willcontinue either until the actuating force is reduced, or the mainfollower comes into abutment with the outer end yof the spring cagecasting, whereupon the pressure will be transmitted directly through thespring cage to the correspondingmain follower, thereby preventing themain spring resi-stance F from being driv-en solid.

In release, the main and auxiliary springs efectively restore all of theparts to normal position, the lugs 26 on the shoes B limiting theoutward movement thereof to properly space the same with reference tothe surfaces 123 of the wedge D. In this connection, it is pointed outthat during compression of the mechanism a greater spreading action willbe exerted on the shoes B when the faces 23 and 12,3 of the shoes andwedge respectively come into engagement, due Ato the effective wedgingangle of the faces 23 and 123 being keener than the wedging angle vofthe faces 24 and 124. Y

The light preliminary-action provided in connection with my improvedshock absorbing mechanism particularly adapts the same for use inconnect-ion with passenger cars, inasmuch as the same effectivelycushions the numerous light shocks, as well as the heavier shocks, towhich passenger cars are subjected.-

Ihile I have herein shown and described whatI now consider the preferredmanner of carrying out my invention, the same is merely illustrative,and I contemplate all changes and modifications that come within thescope of the claims appended hereto.

I claim:

1. In a friction shock absorbing mechanism,the combination with a columnelement having friction surfaces thereon; of a main spring resistance;an auxiliary spring resistance; a plurality of relatively movablecooperating friction elements, certain of which engage with the frictionsurfaces of said column element and are movable longitudinally thereofand resisted in their movement by said main spring,'relative movement ofsaid friction elements being resisted by said auxiliary spring; andwedge pressure transmitting' means cooperating` with each of saidrelatively movable friction elements during the conpression stroke ofthe mechanism.

2. In a friction shock absorbing mechanism, the combination with afriction member; of a plurality of cooperating relatively movablefriction elements, certain of which haveA engagement with said memberand are relatively movable thereto; pressure transmitting means having awedgefface cooper- I relatively movable thereto; pressure' trans-V,mittmg means4 having a wedge face cooperating with said last namedelements and also having additional wedge faces cooperating with theremaining elements, said first named wedge rface being normallydisengaged from the cooperating elements to per` mit relative movementof said cooperating elements and provide for preliminary action during`compression of'the mechanism; a main spring resistance opposingrelative vmovement of the friction member and vthe elements havingengagement therewith; and an auxiliary spring resistance opposingrelative movement of said cooperating friction elements. v Y I 4. In afriction shock absorbing mechanism, the combination with a frictionmember; ofa plurality of cooperating, relatively movable frictionelements, certain of which have engagement with said member and arerelatively movable thereto; pressure ltransmitting means having a wedgeface cooperating with saidV last named elements and also having`additional wedge faces cooperating with the remaining elements, saidrst named wedge face being normally disengaged from the cooperatingelements to permit relative movement of said cooperating elementsandprovide for preliminary Vaction during compression of the mechanism; aspring resistance opposing relative movementv of said friction 'memberand the elements having engagement therewith; and an auxiliary springresista-nce opposing relative movement of said cooperating frictionelements.

5. In a friction shock absorbing mechanism, the combination with afriction member; of a plurality of cooperating, relatively movablefriction element-s, certain ofv which have engagement with saidmember'and are relatively movable thereto; pressure transmitting meanshaving a wedge face adapted to cooperate with the friction elementsengaging the friction member and having wedge faces cooperating withsaid remaining friction-elements, said last named wedge faces beingangularly disposed to said rst "named: face; a main spring resistanceopposing relative movement of the friction member and the elementshaving engage- `ment therewith; and Yan auxiliary spring re- Y sist-anceopposing rela-tive movement of sait cooperatingl friction elements.

6. In a friction shock absorbing mechanism, the combinati-on with afriction shell having inwardly converging friction surfaces; ofva.Vfriction wedge system coacting with the shell, saidsy-stem including aphirality ofV shoes having limited relative movenient, and 4spreadingmeans, said spreading meansvanfd each of said shoes having cooper-atingwedge faces; main spring resistance; pressure transmitting means; andanradditional spring resistance operatively i .interposed vbetweencertainof said shoes vand Y the pressure transmitting means, saidpressure transmitting means directly coacting with the remaining shoesto transmit the actuating force .directly therefrom to the main springresistanceafter a predetermined compression of saidl additional spring.

K 7.l In ya frictionjrshock absorbing mecha-Vv nism, thel combinationwith a friction elej Y ment; ofa friction wedge system coactingVWithsaid element, said system' including a fao fplurality of frictionshoes having limited relative movement and spreading means Co'-.operating `with the shoes, said spreading means and each of said shoeshaving cooperating Wedge faces; pressure transmitting'ineans; springresistance elements co-V operating with said pressure transmittingmeans5- one of said elements resisting inward movement of certain vofV.said shoes, and the other spring resistance element opposing -inwardVmovement lof the remaining slices, said pressure transmitting element edirectly coacting with said last named shoes.

r8. In a friction shock absorbing mecha-y nism, the combination with afriction element having a plurality of friction-surfaces; of frictionshoes eng-aging said friction snrfaces ,and relatively movable to saidelement; a main spring resisting relative movement of said shoesv andsaid element; additional shoes frictionally enga-ging said eli-rstnam-edshoes; anradditional spring resisting movement of s-aidadditionalshoes withY reference to the shoes engaging said friction .surfaces; andWedge pressure transmitting means having 'wed-fige faces adaptedtosnc-KV y,

cessivel f renOa-Oe said additional and firstY named shoes respectivelyto aotuate the same rin sequence and effect successive .compression ofsaid additional and main spring resist ance elements. e

In -a friction shock absorbing "mechanisin, the combination with afriction Selefaces; of two sets of friction shoes,- said sets havingcooperating friction `surfaces `and being relatively movable withreference to each other, and one vof said sets Vhaving*frictional'engagenient with the friction surfaces of said element; a inain spr-ingresistance cooperating with said last named setof shoes.; a secondspring resistance cooperating wit-hithe other .set of-shoes; a Wedgemember having a plurality of Wedge faces cooperating with the two setsof shoes, the .cooperating wedge faces lof said wedge and shoes which`en-gnige .the friction `element being normally separated to .permitlimited nient having aV plurality fof friction surrelative movement ofsaid two sets of shoes A dii-ring vpreliminary action of the mechanisrn.f Y

In witness that claim the foregoing I have hereunto subscribed my namethis 17th .clay of hiarch, 1925. v

YJoinv oooNNoR.

